Currently, when registering with a network, a mobile terminal needs to go through processes such as scanning frequency channels, decoding a system broadcast message, saving a frequency channel, camping on a cell, and sending a registration message, where the process of sending a registration message further includes a process of requesting a channel and a process of registration authentication. Because a cell has limited network resources, when the cell is overloaded and the network resources are insufficient in a process of registering with a network, the network sends a channel allocation rejection message to the mobile terminal, and does not allocate a network resource to the mobile terminal, so as to reject access from the mobile terminal.
In the prior art, after receiving the channel allocation rejection message sent by the network, the mobile terminal re-initiates a process of registering with the network. For the purpose of accelerating network search, the mobile terminal preferentially scans frequency channels that are successfully decoded before, sorts, according to signal strength, cells of available frequency channels that are obtained by means of scanning, and tries the cells one by one to determine whether one cell can be camped on.
However, in the re-registration process, if signals are strong in the cell with which registration failed before and that has limited network resources, though a frequency channel with abundant network resources exists in the network, the mobile terminal still selects the cell with limited network resources to perform registration, which leads to a failure in registering the mobile terminal with the network.